Eldritch the Rectifier (Hell)
Chance: 0.0005062% (1:197567)
with 0% MF
The best monster to get tals armour is baal with
Baal 0.0533374% 1:1875

If you want tals ammy, try killing andy in hell, she has the best chance other then dury(good luck finding him though) with
Andariel (Hell) 0.0118948% 1:8407
also if you are doing eldritch he has
Chance: 0.0009909% (1:100918)

While this is still about the best online calculator available, it is not correct, especially for SuperUnique monsters. It has their mlvls wrong, which means it is in danger of getting whether a monster can drop a particular item wrong. For example, it thinks Pindleskin can drop Tyrael's might, which he can't.

It is a reasonably good source for "best chance" though, provided you use it with caution and check that the monster they say has the "best chance", can actually drop what you are looking for.